1. Field of the Invention
This disclosure pertains to methods and systems for the management of chemicals in processing environments, such as semiconductor fabrication environments.
2. Related Art
In various industries, chemical delivery systems are used to supply chemicals to processing tools. Illustrative industries include the semiconductor industry, pharmaceutical industry, biomedical industry, food processing industry, household product industry, personal care products industry, petroleum industry and others.
The chemicals being delivered by a given chemical delivery system depend, of course, on the particular processes being performed. Accordingly, the particular chemicals supplied to semiconductor processing tools depend on the processes being performed on wafers in the tools. Illustrative semiconductor processes include etching, cleaning, chemical mechanical polishing (CMP) and wet deposition (e.g., chemical vapor deposition, electroplating, etc.).
Commonly, two or more fluids are combined to form a desired solution for a particular process. The solution mixtures can be prepared off-site and then shipped to an end point location or a point-of-use for a given process. This approach is typically referred to as batch processing or batching. Alternatively, and more desirably, the cleaning solution mixtures are prepared at the point-of-use with a suitable mixer or blender system prior to delivery to the cleaning process. The latter approach is sometimes referred as continuous blending.
In either case, accurate mixing of reagents at desired ratios is particularly important because variations in concentration of the chemicals detrimentally affect process performance. For example, failure to maintain specified concentrations of chemicals for an etch process can introduce uncertainty in etch rates and, hence, is a source of process variation.
In today's processing environments, however, mixing is only one of many aspects that must be controlled to achieve a desired process result. For example, in addition to mixing, it may be desirable or necessary to control removal of chemicals from a processing environment. It may also be desirable or necessary to control temperatures of chemical solutions at various stages in the processing environment. Currently, chemical management systems are not capable of adequately controlling a plurality of process parameters for certain applications.
Therefore, there is a need for methods and systems for managing chemical conditioning and supply in processing environments.